JPH0822662B2 - Airbag inflator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a gas generator, and more particularly to
The present invention relates to an inflator that inflates an airbag that protects an occupant of a vehicle.

[0002]

BACKGROUND OF THE INVENTION It is well known to use an inflated airbag to protect the occupants of a vehicle during rapid vehicle deceleration, such as during a collision. Such an airbag restrains an occupant of the vehicle from moving during a collision. The airbag is typically inflated by actuating a gas generating material to generate gas. The gas generating material is housed in an airbag inflator.

[0003]

Air bag inflators are generally equipped with an ignition device that is electrically actuatable and ignites a gas generating material. The inflator includes a structure for fixing the ignition device to the housing of the inflator. It would be desirable to have a compact, lightweight, inexpensive, and easy to assemble structure for securing an ignition device to a housing.

An airbag inflator for protecting a vehicle driver is attached to a steering wheel of the vehicle.
It is desirable for such an inflator to be small and lightweight so as to minimize the rotational mass of the steering handle assembly. Also, the inflator must consist of a minimum number of parts that are easy to manufacture, low cost, and easy to assemble.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an inflator for inflating an airbag. The inflator includes an inflator housing. A quantity of gas generating material is placed in the housing. The gas generating material, when ignited, generates a gas that inflates the airbag. The ignition device can be activated to ignite the gas generating material.

Such an inflator includes means for fixing the ignition device to the housing. The fastening means comprises a weldable material and comprises a welding adapter which is welded to the housing. The fastening means also comprises a plastic material which attaches the ignition device to the welding adapter. The plastic material is adhered to both the firing device and the welding adapter to attach the firing device to the welding adapter. In the preferred embodiment, the weld adapter is welded to the cover which is part of the inflator housing. The cover is welded to another weldable component of the inflator housing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is an airbag inflator, and more particularly,
The present invention relates to an inflator that inflates an airbag that protects a driver of a vehicle. The present invention can be applied to various inflator structures. As an example of the present invention, FIG.
In the figure, an inflator 10 is shown. Airbag 12
Are folded around the inflator 10. The cover 14 encloses the airbag 12 and the inflator 10. Inflator 10, airbag 12 and cover 14
Is a component of a module mounted on the steering wheel 16 of the vehicle.

When the vehicle is rapidly decelerated, such as during a collision, the inflator 10 is actuated, producing a large amount of gas. The gas from the inflator 10 inflates the airbag 12. When the airbag 12 starts to inflate, the airbag 12 breaks the weak portion of the cover 14. One of these weakened portions is shown at 18 in FIG. As the airbag 12 continues to inflate, it is known to move into the space between the driver of the vehicle and the steering wheel 16 and restrain the driver's movement.

The inflator 10 (FIG. 2) includes a housing 40. The housing 40 consists of three components, a diffuser cup 42, a combustion cup 44, and a combustion chamber 46 cover. Diffuser cup 42, combustion cup 44, and combustion chamber cover 46
Is formed of a metal such as UNS S30100 stainless steel.

The diffuser cup 42 is generally cup-shaped and has a cylindrical side wall 50 extending around a central axis 52 of the inflator 10. The sidewall 50 extends between a flat top wall 54 and a flat lower flange 56. The inner annular surface 55 of the upper end wall 54 of the diffuser cup 42 defines a central opening 57 in the upper end wall 54 of the diffuser cup 42. The end wall 54 and the flange 56 are generally parallel to each other and perpendicular to the axis 52. An annular array of gas outlets 58 is formed in the upper portion of the diffuser cup sidewall 50.

The combustion cup 44 is substantially cup-shaped and is arranged inside the diffuser cup 42. The combustion cup 44 includes a cylindrical side wall 60 extending around the axis 52. The cylindrical side wall 60 extends between a flat top wall 64 and a flat lower flange 66. The top wall 64 and lower flange 66 are generally parallel to each other and perpendicular to the axis 52. An annular array of outlets 68 is formed in the lower portion of the combustion sidewall 60.

The upper end wall 64 of the combustion cup 44 is welded to the annular surface 55 of the upper end wall 54 of the diffuser cup 42 at a peripheral weld location 70 by continuous welding, preferably laser welding. Combustion cup flange 66 is welded to diffuser cup flange 56 at peripheral weld location 72 by continuous welding, preferably laser welding.

Combustion chamber cover 46 is a generally flat metal piece having a circular central portion 80 and a parallel but slightly eccentric circular outer flange 82. A circular opening 84 is formed in the central portion 80 of the chamber cover 46. The outer flange 82 of the chamber cover 46 is welded to the combustion cup flange 66 at a peripheral weld location 86 by continuous welding as well, preferably laser welding.

The hermetically sealed canister 90 replaces the combustion cup 44.
Placed inside. The canister 90 consists of two components, a lower canister portion 92 and a cover 94. The radially outer edge of the canister cover 94 is crimped to the adjacent edge of the canister lower portion 92 to hermetically seal the canister 90. The canister 90
Is preferably manufactured from relatively thin aluminum.

The lower portion 92 of the canister has a cylindrical outer wall 96 adjacent and inside the sidewall 60 of the combustion cup. The sidewall 96 has a reduced thickness in the region of the sidewall 60 of the combustion cup adjacent the outlet 68. The lower portion 92 of the canister also has a cylindrical inner wall 98 spaced radially inward from the side wall 96. The side wall 98 has a thin portion in a region adjacent to the ignition device 142.

A flat ring-shaped lower wall 100 of the lower portion 92 of the canister interconnects the side wall 96 and the inner side wall 98. A circular inner top wall 102 of the lower portion 92 of the canister extends radially inward from and caps the inner wall 98. Inner top wall 102 and cylindrical inner wall 98 define a central recess 104 that opens downwardly in canister 90.

The canister cover 94 has a substantially circular shape. A recess 106 is located in the center of the canister cover 94. Recessed portion 10 for accommodating automatic ignition material is recess 10.
6 placed in and aluminum foil tape 109
It is retained in the recess 106 by a piece of.

A plurality of annular disks 110 of gas generating material.
Are successively stacked in the canister 90. An annular cushion 112 is located between the top gas generating disk 114 and the inside of the canister cover 94. The disk 110 is made of a known material that produces nitrogen gas when ignited. While many types of gas generating materials can be used, those disclosed in US Pat. No. 3,895,098 are suitable gas generating materials.

The annular prefilter 120 is a canister 9.
It is located within 0. The pre-filter 120 is located radially outward of the gas generating disk 110 and also in the canister 9.
It is located radially inward of the outer wall 96 of zero. A small annular space exists between the prefilter 120 and the outer wall 96.

An annular slug screen, generally indicated at 122, is disposed outside the combustion cup 44 and within the diffuser cup 44. The slag screen 122
Lies radially outward of the outlet 68 and lies in contact with the sidewall 60 of the combustion cup. However, the slag screen 122 may be spaced from the outlet 68 of the combustion cup sidewall 60.

An annular final filter assembly, shown schematically at 124, is located above the slug screen 122 and inside the diffuser cup 42. The final filter assembly 124 is radially inward of the gas outlet 58 on the sidewall 50 of the diffuser cup 42. The final filter assembly 124 is multiple layers of various materials. The layers extend along the sidewall 50 of the diffuser cup and are located inside the sidewall. The detailed construction of final filter assembly 124 does not form part of the present invention and is therefore not described in detail.

An annular filter shield 126 extends radially inwardly from the diffuser cup sidewall 50, separating the final filter assembly 124 and slug screen 122. An annular graphite seal 128 seals the gap between the top edge of the final filter assembly 124 and the inside of the diffuser upper flange 54. Another annular graphite seal 130 seals the gap between the lower edge of the final filter assembly 124 and the upper portion of the filter shield 126.

The inflator 10 includes an ignition device assembly 140.
It has. The igniter assembly 140 projects through the opening 84 in the chamber cover 46 and into the central recess 104 of the canister 90. The ignition device assembly 140 is
It is welded to the central portion 80 of the chamber cover 46 at the peripheral weld location 144 by continuous welding, preferably laser welding.

The ignition device assembly 140 includes an ignition device 142.
It has. The ignition device 142 is the ignition device assembly 1
A pair of wire leads 146 extending outwardly from 40 are provided. The wire lead 146 can be connected to a collision sensor (not shown). The wire lead 146 is connected to a resistance wire embedded within the ignition material of the ignition device 142. The firing device 142 can be of any suitable known construction. A thin plastic film (not shown) is placed on the outside of the upper portion of the ignition device 142,
Ground the ignition device 142 to prevent metal-to-metal contact that renders the inflator 10 inoperable. Ignition device 142
May have a pin (not shown) connected to the collision sensor instead of the wire lead.

During a vehicle crash or other sudden deceleration, current flows from the crash sensor through wire leads 146 or pins (not shown) to the ignition device 142. The resistance wire explodes the pyrotechnic material, which causes the explosive of the firing device 142 to explode rapidly. The explosion of such explosives produces a hot gas product which is ignited by an ignition device 1423.
Flows outwardly from the inner top wall 10 of the canister 90.
2 and the inner wall 98 are ruptured. The hot gas from the igniter 142 ignites the disk 110 of gas generating material. The disk 110 made of a gas generating material suddenly generates a large amount of another high temperature gas.

The gas pressure is controlled by the side wall 96 of the canister 90.
Urging the side wall 96 radially outwardly against the side wall 60 of the combustion cup. As a result, the canister 90
Thin sidewall 96 of the cup breaks or blows off at the outlet 68 of the sidewall 60 of the combustion cup. Side wall 96 adjacent to the outlet 68
Due to the small thickness of the sidewall, this sidewall portion 96 will rupture before the rest at the desired pressure. Next, the disk 110
The gas produced by the combustion of the gas flows radially outward through the prefilter 120. The prefilter 120
Removes some of the combustion products of the igniter 140 and the gas generating disk 110 from the flowing gas. The prefilter 120 also cools the flowing gas. As the gas cools, the molten product deposits on the prefilter 120. The gas passes through the outlet 68 and the slag screen 12
Flow into 2

The slag screen 122 removes and captures particulates from the flowing gas. The slag screen also cools the flowing gas. As the gas cools, the molten combustion products deposit on the slag screen 122. A filter shield 126 between the slag screen 122 and the final filter assembly 124 creates turbulent gas flow in and out of the slag screen 122. The turbulent gas flow facilitates retaining relatively heavy particulates within the lower portion of the slag screen 122 and diffuser cup 42.

The gas flows axially upward from the slag screen 122 to the final filter assembly 124. next,
The gas flows radially outward through the final filter assembly 124, which removes small particulates from the gas. The final filter assembly 124 also causes the gas to cool further, so that the molten product in the gas deposits on a portion of the final filter assembly 124. The annular row of gas outlets 58 introduces a gas flow into the airbag 12 to inflate the airbag 12.

In accordance with the present invention, the ignition device 142 includes a welding adapter 150 and a body 15 of injection molded plastic material.
It is fixed to the hanging cover 46 by means of two. The plastic material 152 secures the ignition device 142 to the welding adapter 150.

Weld adapter 150 (FIG. 4) includes socket 154 and flange 156. The socket 1
54 has a cylindrical outer peripheral surface 158 and an inner end surface 160 extending in the radial direction. Conical surface 162 defines a portion of passage 164 through socket 154. A peripheral groove 166 divides the conical surface 162 into an axially inner portion 168 and an axially outer portion 170. The conical surface 162
Are tapered radially outward as they extend upwardly from the flange 156 into the recess 104.

The flange 156 of the welding adapter 150 is
It has a radially extending inner surface 174, a cylindrical circumferential outer surface 176, and a radially extending outer end surface 178. Annular axially extending surface 180 and flange 156
A central annular radial extension surface 182 defines a portion of passage 164 and completes the passage. These extension planes 1
80, 182 also define an outwardly facing shoulder 184 on the welding adapter 150.

The welding adapter 150 is a UNS S304.
It consists of a weldable material suitable for cold heading, such as 30 stainless steel. The plastic material 152 is a structural member that adheres to both the welding adapter 150 and the ignition device 142 when cooled. Plastic material 1
52 can be a 40% glass filled polyphenylene sulfide resin sold under the registered trademark Ryton R4XE as Phillip 66 plastic. Other materials that are injection moldable and adhere to the firing device 142 and welding adapter 150 are also suitable for use.

To secure firing device 142 to welding adapter 150 (FIG. 3), firing device 142 and welding adapter 150 are positioned relative to each other in a mold (not shown). The ignition device 142 is installed in the passage 1 of the welding adapter 150.
Extend through 64. Molten plastic material 1
52 is injected into the mold. The plastic material 152
Is an end surface 160, a conical surface 162 and a welding adapter 15
It is adhered to the 0 planes 180 and 182. Plastic material 1
The portion 186 of 52 includes the ignition device 142 and the welding adapter 1.
Located within the passageway 164 between 50. The plastic material portion 186 includes the firing device 142 and the welding adapter 1.
Adhere to 50 conical surface 162. Plastic material 1
Another portion 188 of 52 is the shoulder 18 of the welding adapter 150.
4 and is adhered to the surfaces 180, 182 to form a shoulder 184. A further portion 190 of plastic material flows into the groove 166 of the welding adapter 150,
Lock the plastic 152 onto the weld adapter 150.

After fixing the ignition device 142 to the welding adapter 150, the welding adapter 150 is attached to the combustion chamber cover 4.
Weld to 6. The inner surface 174 of the welding adapter 150 has an outer surface 19 that extends radially through the central portion 80 of the cover 46.
2 is engaged. The flange 156 has a circumferential welding position 144.
Are continuously welded to the cover 46. Next, the cover 46
Are welded to the combustion cup 44. Thereby, the ignition device 1
42 is fixed in place in the inflator 10.

With the igniter 142 secured in place within the inflator 10, the plastic material 152 is attached to the axial end surface 160 and conical surface 162 of the welding adapter 150.
To prevent the firing device 142 from moving axially outwardly of the inflator 10 from its desired position. This prevents the ignition device 142 from being removed from the inflator 10 without permission or at an inappropriate time. or,
The plastic material 152 engages the axially outwardly facing shoulder 184 of the weld adapter 150 and prevents the firing device 142 from moving from its desired position into the inflator 10. This prevents the ignition device 142 from being accidentally pushed into the inflator 10.

As shown in FIG. 5, the flange 156 of the welding adapter 150 can be radially cut at spaced locations 196, 198 to form the protrusion 200.
This optional projection 200 is used to steer the vehicle steering wheel 1
It is used as an operator identification means for placing the assembled inflator 10 in the airbag module attached to the 6. Such a feature is advantageous, for example, when the polarized electrical pin connector is used in an ignition device. Alternatively, the welding adapter 150 can be rounded.

By welding adapter 150 to the cover and welding cover 46 to combustion cup 44, a barrier is provided to prevent contamination of the inflator 10 ignition system. It is difficult to obtain such a barrier by the known threaded or crimped connection means of the ignition device to the inflator housing. Also, welding provides a tamper-proof joint, making it more difficult to improperly disassemble the inflator. This is also an advantage over inflators that utilize threaded or crimped fittings on the firing device.

Injection molded plastic material 15 used to secure ignition device 142 to welding adapter 150.
2 is extremely lightweight. As described above, the present invention provides the ignition device 142 and the plastic injection molding material 1.
An ignition device assembly 140 is provided that comprises a small number of components including only a welding adapter 150 interconnected by 52. Weld adapter 150 is easily welded directly to cover 46, while cover 46 is easily welded directly to combustion cup 44. The structure is relatively inexpensive and lightweight, yet easy to assemble.

From the above description of the invention, those skilled in the art will perceive improvements, modifications and applications of the invention. Such improvements, modifications and applications within the technical scope are intended to be covered by the appended claims.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a steering handle with an inflatable occupant restraint module incorporating an inflator constructed in accordance with the present invention.

2 is a cross-sectional view showing a partial cross-sectional view of the inflator of FIG.

3 is an enlarged view of a portion of the firing device assembly of the inflator of FIG. 2 including a firing and welding adapter.

4 is a cross-sectional view of the welding adapter of FIG.

5 is an elevational view of the welding adapter of FIG.

[Explanation of symbols]

10 inflator 12 airbag 14 cover 16 steering handle 40 housing 42 diffuser cup 44 combustion cup 46 combustion chamber 50 side wall 54 upper end wall 55 inner annular surface 56 lower flange 57 center opening 58 gas outlet 60 side wall 64 upper end wall 66 lower flange 68 outlet 70 peripheral welding position 72 peripheral welding position 80 central portion 82 outer flange 84 opening 86 peripheral welding position 90 canister 92 lower canister portion 94 canister cover 96 outer wall 98 inner wall 100 lower wall 102 top wall 104 center recess 106 recess 108 Storage part 109 Foil tape 110 Annular disk 112 Annular cushion 114 Gas generating disk 120 Annular pre-filter 122 Slug screen 124 Final filter assembly 126 Filter Shield 128 Graphite Seal 130 Graphite Seal 140 Ignition Device Assembly 142 Ignition Device 144 Edge Welding Point 146 Wire Lead 150 Welding Adapter 152 Plastic Material

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Timothy A. Swan, East Fairfield Street, Mesa, 85205, Arizona 85205, USA (72) Inventor Jerome W. Emery, Arizona, USA 85281, Temp, West West Seventeenth Place 536 (56) Reference JP-A-2-155861 (JP, A) JP-A-2-225158 (JP, A)

Claims (17)

[Claims] And 1. A inflator housing, disposed within said housing, when ignited, a quantity of gas generating for generating gas for inflating the air bag
Material and the firing device operable to ignite said gas generating material, said a firing device airbag inflator Bei <br/> Ru example and means for securing said housing, said anchoring means Is a welding adapter welded to the housing, and for attaching the ignition device to the welding adapter,
Airbag inflator, characterized in that it comprises a plastic material interposed between them, the. 2. The apparatus of claim 1, wherein the plastic material is attached to both the firing device and the welding adapter, thereby attaching the firing device to the welding adapter. . 3. The apparatus of claim 2, wherein the plastic material is an injection molding material that is at least partially injected between the ignition device and the welding adapter.
Ri, and wherein the injection-molding material is injection molded material Ryotai which solidified becomes adhered to the ignition device and the welding adapter. 4. The apparatus of claim 2, wherein the welding adapter extends from the socket portion for receiving the firing device and the socket portion and welds the housing in a first position. apparatus characterized by and a flange portion secured to. 5. The apparatus of claim 4, wherein the welding adapter prevents movement of the firing device in a first direction moving from the first position toward the housing. device arming device is characterized in that it comprises, means for preventing movement from the first position to the second direction of movement in a direction Ru exits the housing. 6. The apparatus according to claim 5, wherein the ignition is performed.
Means for preventing movement of the device in the first direction is the first
Of the surface of the weld adapter facing a direction substantially away from the direction, movement of the plastic material in engagement with the surface, thus the first direction away from the first position of the ignition device
An apparatus comprising a portion of a plastic material that prevents movement of the material . 7. The device according to claim 5, wherein the ignition is performed.
Means for preventing movement in the second direction of the apparatus, first the and conical surface of the socket portion of the weld adapter, movement of the engaging front Symbol plastic material into the conical surface, thus the ignition device Movement in a second direction away from position 1,
Apparatus characterized by and a part of the plastic material that resists. In 8. within the airbag inflator housing, and the ignition device assembly <br/> ignite the gas generating material a quantity, and a cover of the housing, to become and the housing cover weldable material and welded welded adapters, an operable arming device as capable of igniting a gas generating material, the flop <br/> plastic injection molding material Ryotai adhered to the ignition device and the welding adapter, the welding adapter An ignition device attached to the ignition device assembly . 9. The ignition device assembly of claim 8, wherein the welding adapter extends through the ignition device.
And a socket portion having a surface means for defining a that passage, and the flange portion Ru Tei is welded to the housing cover,
An ignition device assembly, comprising: 10. The ignition device assembly according to claim 8, wherein the cover has an opening through which the ignition device penetrates and projects, and a flange portion for welding to an inflator . An ignition device assembly, comprising: 11. A inflator housing, disposed within said housing, when ignited, the gas generating material a quantity that generates gas for inflating the air bag, operable can generate the gas generating material Do a firing device, a fixed weld adapter to the ignition device, Ru and a welding adapter for securing a welded to the housing the ignition device in the housing at a first position Airbus
And a welding adapter for inflating the bag from the first position of the ignition device into the housing.
Means for blocking movement in a first direction toward the outside of the housing from the first position of the ignition device.
And wherein the means for preventing the movement in the second direction toward, further comprising a. 12. An apparatus according to claim 11, is bonded to the weld adapter and the ignition device, characterized in that it comprises a plastic material Ryotai <br/> to stick to the welding adapter the ignition device And the device. 13. An apparatus according to claim 12, wherein the first hand stage you prevented from moving in the direction of the ignition device,
Said welding adapter surface facing a direction away substantially from the first direction, it engages the surface of the plastic material
Moving, thus apparatus characterized by comprising a portion of the plastic material which the ignition device is prevented from moving, in a first direction toward the housing from the first position. 14. An apparatus according to claim 12, the second hand stage you prevented from moving in the direction of the ignition device, and the conical socket of the weld adapter, engaging in the conical socket combined with the movement of the plastic material, thus towards outside the housing from the first position of the ignition device
Device characterized in that it comprises a part, a plastics material that resists movement in the second direction. 15. The device of claim 14, wherein the conical socket has a conical surface that tapers radially outward as the conical socket (a) extends axially inward of the inflator housing. If, (b) and a surface means defining a circumferential groove extending radially outwardly from the conical surface, the welding the plastic material partially received within the groove of the plastic material A device characterized by being locked to an adapter. 16. The apparatus of claim 12, wherein the firing device extends through an axial passage of the welding adapter and the plastic material extends the passage between the firing device and the welding adapter. At least partially injected into
Injection molding material, the injection molding material is solidified
An injection molded plastic material body adhered to the outer surface of the ignition device and the inner surface of the welding adapter. 17. The apparatus according to claim 12, including projection means provided on the welding adapter for selectively orienting the inflator in an oblique direction.